The investigation of a tuberculosis outbreak in the closed environment of a U.S. Navy ship, 1987.

A sailor on a U.S. Navy ship had smear-positive, cavitary, pulmonary tuberculosis. Contact investigation of the entire ship's crew found 216 new reactors to tuberculin skin test (24.5%) among 881 previously tuberculin-negative sailors. The risk for new infection was highest among sailors in the patient's department (relative risk, 4.4; 95% confidence interval 3.7, 5.3); 95% (15/16) of sailors in his division were new reactors. While crewmembers in all departments were at risk for a new tuberculosis infection, working and berthing in compartments that were distant from those of the index case were protective. The ship's closed ventilation system contributed to the outbreak.